Part 7: Quality Assurance & Testing

How do you know your application works? Can you prove it? Does it work when:

• The user has a slow internet connection?
• They log in on two different devices at the same time?
• 100 people try to upload videos at once?

These are questions developers can’t answer by simply looking at code. And if you wait for users to report issues, it’s already too late.

When I built shotsrv, my solo project for taking screenshots of URLs, I didn’t have a QA process. I’d test the basic functionality on my machine, deploy it, and wait for users to report bugs. And they did. Usually via emails that started with “Hey, your app is broken.”

Here’s the thing: if one user takes the time to email you, it probably means hundreds of others tried, failed, and gave up. That’s why quality assurance (QA) is critical. It’s not just about finding bugs, it’s about proving your application works under real-world conditions.

In this article, we’ll explore how to ensure FamFlix, our Netflix-like platform for families to share private videos, is reliable, performant, and secure, before it reaches real users.

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The Solo Project Mindset: Testing as an Afterthought

In personal projects, testing is often informal—if it happens at all. You might:

• Test on your machine: If it works for you, it’s good enough.
• Ignore edge cases: What happens if the user uploads a corrupted file? Who cares!
• Rely on user feedback: If something breaks, they’ll let you know.

This approach is tempting, but it’s risky. Without proper QA, you might:

• Miss critical bugs that only appear under specific conditions.
• Overlook performance issues that make the app unusable for real users.
• Ship vulnerabilities that expose user data.

For example, when I built shotsrv, I didn’t test how it handled concurrent requests. The result? My server crashed the first time 10 users tried to take screenshots at once.

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The Team Project Reality: QA as a Core Discipline

In a team project, QA isn’t an afterthought. It’s a core discipline. It ensures the application:

1. Works as expected: All features function correctly under normal conditions.
2. Handles edge cases: The app behaves gracefully when things go wrong (e.g., network failures, invalid inputs).
3. Scales under load: The system performs well with hundreds or thousands of users.
4. Stays secure: User data is protected from common vulnerabilities (e.g., SQL injection, XSS).

For FamFlix, this means implementing a comprehensive QA process that includes the following:

1. Automated Testing

Automated tests catch regressions and ensure new code doesn’t break existing functionality.

• API Testing: Use Jest to test backend endpoints (e.g., video upload, authentication).
• UI Testing: Use Cypress to test frontend flows (e.g., upload → playback).
• Unit Testing: Write tests for individual components (e.g., FFmpeg transcoding logic).

Success Metric: 90% test coverage for critical paths.

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2. Performance Testing

Performance tests ensure the system can handle real-world traffic.

• Load Testing: Use Locust.io to simulate 100+ concurrent uploads and streams.
• Stress Testing: Push the system to its limits to identify bottlenecks (e.g., slow database queries).
• Latency Testing: Measure API response times under different network conditions.

Success Metric: Videos process within 5 minutes of upload, even under load.

3. Security Audit

Security tests protect user data and ensure compliance with privacy laws.

• Penetration Testing: Simulate attacks (e.g., SQL injection, XSS) to identify vulnerabilities.
• Code Review: Ensure sensitive data (e.g., passwords, API keys) is encrypted and stored securely.
• Compliance Check: Verify the app meets GDPR and other regulatory requirements.

Success Metric: Passes security audit with no critical vulnerabilities.

4. User Acceptance Testing (UAT)

UAT ensures the app meets user expectations and works in real-world scenarios.

• Real Devices: Test the app on a variety of devices (e.g., Grandma’s iPad, Dad’s Android phone).
• Real Users: Invite families to test invite flows, video playback, and commenting features.
• Feedback Loop: Gather feedback and prioritize fixes before launch.

Success Metric: 95% of testers can upload, stream, and interact with videos without issues.

Why This Process Matters

At first glance, QA might feel like a bottleneck. But it’s the difference between an app that works and an app that delights. By investing in QA, we:

• Catch bugs early: Fixing issues in development is cheaper and faster than fixing them in production.
• Ensure scalability: Performance testing prevents crashes during peak usage.
• Build trust: A secure, reliable app keeps users coming back.

For example, if we’d skipped QA for FamFlix, we might’ve shipped an app that crashes when 100 users try to upload videos at once. Instead, we’re delivering a platform that families can rely on for years to come.

Coming Up Next…

In Part 8, we’ll dive into Deployment Planning & Infrastructure Setup: how to prepare for a smooth launch and ensure the platform is resilient, scalable, and secure.

In the meantime, ask yourself:
If I built FamFlix alone, what issues would I overlook? And how would that hurt real users?

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Your Turn
Have you ever worked on a project where poor QA caused chaos? Share your story in the comments!

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